Clinical outcomes by race in hypertensive patients with and without the metabolic syndrome: Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

ALLHAT: still providing correct answers after 7 years

PURPOSE OF REVIEW

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is re-evaluated considering information from recent subgroup and exploratory analyses, other new clinical trials, and meta-analyses. The ALLHAT analyses specifically emphasize heart failure findings, results in Black participants and those with chronic kidney disease, selection and doses of thiazide and similar diuretics, and the association of antihypertensive drug use with new-onset diabetes and its cardiovascular consequences.

RECENT FINDINGS

The initial ALLHAT conclusion, that thiazide diuretics are superior to angiotensin-converting enzyme inhibitors (ACEIs), calcium antagonists (CCBs) and alpha-blockers in preventing one or more major clinical outcomes, including heart failure and stroke, and unsurpassed in significantly preventing any cardiovascular or renal outcome, has been further validated for patients with diabetes, renal disease, and/or metabolic syndrome. The evidence is even more compelling for Black patients. New-onset diabetes associated with thiazides did not increase cardiovascular outcomes. The diuretic was superior to all in preventing heart failure with preserved left-ventricular ejection fraction (LVEF) and similar to the ACEI in preventing heart failure with impaired LVEF. It was also unsurpassed in preventing atrial fibrillation.

SUMMARY

The totality of evidence re-affirms the initial ALLHAT conclusion that thiazide and similar diuretics (at evidence-based doses) are the preferred first-step therapy in most patients with hypertension.

Management of high blood pressure in Blacks: an update of the International Society on Hypertension in Blacks consensus statement

Since the first International Society on Hypertension in Blacks consensus statement on the "Management of High Blood Pressure in African American" in 2003, data from additional clinical trials have become available. We reviewed hypertension and cardiovascular disease prevention and treatment guidelines, pharmacological hypertension clinical end point trials, and blood pressure-lowering trials in blacks. Selected trials without significant black representation were considered. In this update, blacks with hypertension are divided into 2 risk strata, primary prevention, where elevated blood pressure without target organ damage, preclinical cardiovascular disease, or overt cardiovascular disease for whom blood pressure consistently <135/85 mm Hg is recommended, and secondary prevention, where elevated blood pressure with target organ damage, preclinical cardiovascular disease, and/or a history of cardiovascular disease, for whom blood pressure consistently <130/80 mm Hg is recommended. If blood pressure is ≤10 mm Hg above target levels, monotherapy with a diuretic or calcium channel blocker is preferred. When blood pressure is >15/10 mm Hg above target, 2-drug therapy is recommended, with either a calcium channel blocker plus a renin-angiotensin system blocker or, alternatively, in edematous and/or volume-overload states, with a thiazide diuretic plus a renin-angiotensin system blocker. Effective multidrug therapeutic combinations through 4 drugs are described. Comprehensive lifestyle modifications should be initiated in blacks when blood pressure is ≥115/75 mm Hg. The updated International Society on Hypertension in Blacks consensus statement on hypertension management in blacks lowers the minimum target blood pressure level for the lowest-risk blacks, emphasizes effective multidrug regimens, and de-emphasizes monotherapy.

Prevention of type 2 diabetes mellitus to reduce cardiovascular morbidity and mortality: a review of the evidence

J Clin Hypertens (Greenwich). 2009;11:512-519. (c)2009 Wiley Periodicals, Inc.Cardiovascular disease accounts for the majority of deaths in patients with type 2 diabetes mellitus. Lifestyle interventions aimed at weight loss and increased physical activity and therapy with antidiabetic drugs have proven effective in reducing the risk of new-onset diabetes in high-risk individuals. Substantial evidence also suggests that drugs that inhibit the renin-angiotensin system, namely angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, also prolong the time to onset of clinical diabetes. An open question is whether delay of new-onset diabetes with antidiabetic or antihypertensive agents reduces cardiovascular morbidity and mortality. A large ongoing study is investigating whether therapy with an oral antidiabetic drug or an angiotensin II receptor blocker reduces the incidence of new-onset diabetes and cardiovascular events in high-risk patients.

Identification of modifiable chronic kidney disease risk factors by gender in an African-American metabolic syndrome cohort

African Americans experience a disproportionately greater burden of chronic kidney disease (CKD) Stage 5 than Caucasians and other minority groups. Precursors to CKD may also be components of metabolic syndrome. This study identified modifiable risk factors for CKD in an African-American metabolic syndrome cohort and compared results by gender. Both men and women (52%) had blood pressure values of 130/80 or higher, impaired fasting glucose levels of 100 to 125 mg/dL (25.5%), and body mass index greater than 25 (98.9%). There was no significant difference between genders. Appropriate clinical management of these factors may prevent or delay the onset of CKD.

The impact of metabolic syndrome on left ventricular myocardial performance

BACKGROUND

Metabolic syndrome (MetS) is common and is associated with increased cardiovascular morbidity and mortality. Recent prospective studies suggested that MetS is associated with increased risk of heart failure. In the present cross-sectional study, we examined the association between left ventricular myocardial performance with MetS.

MATERIALS AND METHODS

A total of 550 non-diabetic subjects, 275 without MetS and 275 with MetS, matched for gender, age and body mass index and free of clinically apparent macrovascular disease were studied. MetS was diagnosed using the NCEP-ATP III criteria. Left ventricular myocardial performance was assessed using the Tei index.

RESULTS

Both men and women with MetS had higher values of the Tei index, indicating worse myocardial performance, in comparison with those without MetS (p < 0.001). Participants with a cluster of more components of the MetS had higher Tei index values than those with fewer components of the MetS. In addition, among normotensive subjects, those with MetS had significantly higher Tei index values than subjects without MetS. Multivariate linear regression analysis, after adjustment for age and body mass index, demonstrated that MetS status and from the individual components of the MetS, high fasting blood glucose levels, higher blood pressure, low high density lipoprotein levels and high waist circumference were associated with worse myocardial performance.

CONCLUSION

MetS is associated with subclinical myocardial dysfunction in both men and women. Strategies to reduce the cardiovascular burden and the risk of heart failure associated with MetS should aim at prevention of the MetS and its related conditions.

Pilot testing of the PRAISEDD intervention among African American and low-income older adults

BACKGROUND AND RESEARCH OBJECTIVE

The incidence of cardiovascular disease (CVD) is particularly high among African American (AA) older adults, and these individuals are least likely to have access to CVD prevention activities. The purpose of this study was to test the feasibility of People Reducing Risk and Improving Strength through Exercise, Diet and Drug Adherence (PRAISEDD), which is geared at increasing adherence to CVD prevention behaviors among AA and low-income older adults.

METHODS

This feasibility study was conducted in a senior housing site, using a single-group repeated-measures design and testing physical activity, diet, medication adherence beliefs and behaviors, and blood pressure at baseline and after a 12-week intervention period. Of 22 participants, mean (SD) age was 76.4 (7.6) years, and most were female (64%) and AA (86%). An intention-to-treat analysis was used.

RESULTS

There were significant decreases in systolic (P = .02) and diastolic blood pressure (P = .01) and a nonsignificant trend toward improvement in cholesterol intake (P = .09). There were no changes in time spent in moderate-level physical activity, sodium intake, medication adherence, or self-efficacy and outcome expectations across all 3 behaviors.

CONCLUSION

The PRAISEDD intervention was feasible in a group of AA and low-income older adults and, after 12 weeks, resulted in improvements in blood pressure. Future research is needed to test a revised PRAISEDD intervention using a randomized controlled design, a larger sample, and a longer follow-up period. The PRAISEDD intervention should be revised to incorporate environmental and policy changes that influence CVD prevention behaviors and explore the impact of social networking as it relates to diffusion of the intervention among participants in low-income housing facilities.

Blood pressure lowering efficacy of reserpine for primary hypertension

BACKGROUND

Many antihypertensive agents exist today for the treatment of primary hypertension (systolic blood pressure >/=140 mmHg and/or diastolic blood pressure >/=90 mmHg). Randomised controlled trials have been carried out to investigate the evidence for these agents.There is, for example, strong RCT evidence that thiazides reduce mortality and morbidity. Reserpine has been used as a second-line therapy in some of those trials. However, the dose-related blood pressure reduction with this agent is not known.

OBJECTIVES

To investigate the dose-related effect of reserpine on blood pressure, heart rate and withdrawals due to adverse events.

SEARCH STRATEGY

The databases CENTRAL, EMBASE, and MEDLINE were searched. We also traced citations in the reference sections of the retrieved studies.

SELECTION CRITERIA

Included studies were truly randomised controlled trials comparing reserpine monotherapy to placebo or no treatment in patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Methods of randomization and concealment were assessed. Data on blood pressure reduction, heart rate,and withdrawal due to adverse effects were extracted and analysed.

MAIN RESULTS

Four RCTs (N =237) were found that met the inclusion criteria. The overall pooled effect demonstrates a statistically significant systolic blood pressure (SBP) reduction in patients taking reserpine compared to placebo (WMD -7.92, 95% CI -14.05, -1.78). Due to significant heterogeneity across trials, a significant effect in diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) could not be found. The SBP effects were achieved with 0.5 mg/day or greater. However, the dose-response pattern could not be determined because of the small number of trials. Data from the trial that investigated Rauwiloid against placebo was not combined with reserpine data from the remaining three trials. This is because Rauwiloid is a different alkaloid extract of the plant Rauwolfia serpentina and the dose used is not comparable to reserpine. None of the included trials reported withdrawals due to adverse effects.

AUTHORS' CONCLUSIONS

Reserpine is effective in reducing SBP roughly to the same degree as other first-line antihypertensive drugs. However, we could not make definite conclusions regarding the dose-response pattern because of the small number of included trials. More RCTs are needed to assess the effects of reserpine on blood pressure and to determine the dose-related safety profile before the role of this drug in the treatment of primary hypertension can be established.

Drug treatment of hypertension in older hypertensives

There is strong evidence supporting the benefit of antihypertensive treatment in older patients. Blood pressure goal and drug selection in the elderly is similar to that in younger populations, but there are a few special considerations in these patients. A number of studies have been conducted to determine the drugs or drug classes most effective for reducing cardiovascular complications in older patients with hypertension. This article reviews the evidence for drug treatment in this population.

Antihypertensive pharmacogenetic effect of fibrinogen-beta variant -455G>A on cardiovascular disease, end-stage renal disease, and mortality: the GenHAT study

OBJECTIVE

The FGB gene codes for fibrinogen-beta, a polypeptide of the coagulation factor fibrinogen, which is positively associated with cardiovascular diseases. Studies show that angiotensin-converting enzyme (ACE) inhibitors lower plasma fibrinogen concentrations, whereas diuretics and calcium-channel blockers do not. As carriers of the FGB-455 minor 'A' allele have higher levels of fibrinogen while ACE inhibitors lower it, we hypothesize that 'A' allele carriers benefit more from antihypertensive treatment with ACE inhibitors than calcium-channel blockers or diuretics, relative to 'GG' genotype individuals.

METHODS

The Genetics of Hypertension Associated Treatment (GenHAT) study [ancillary to Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)] genotyped hypertensive participants for several hypertension-related candidate genes, making this a post-hoc analysis of a randomized trial. In total, 90.1% of the ALLHAT population was successfully genotyped for FGB-455. We included participants (n=30 076) randomized to one of three antihypertensive medications (lisinopril, amlodipine, chlorthalidone), with two treatment comparisons: lisinopril versus chlorthalidone and lisinopril versus amlodipine. The primary outcome of ALLHAT/GenHAT was coronary heart disease, defined as fatal coronary heart disease or non-fatal myocardial infarction, and secondary outcomes included stroke, heart failure, all-cause mortality, and end-stage renal disease (ESRD) with mean follow-up time of 4.9 years. Genotype-by-treatment interactions (pharmacogenetic effects) were tested with the Cox regression.

RESULTS

Stroke: common 'GG' homozygotes had higher risk on lisinopril versus amlodipine [hazard ratio (HR)=1.38, P<0.001], whereas minor 'A' allele carriers had slightly lower risk (HR=0.96, P=0.76; P value for interaction=0.03). Mortality: 'GG' homozygotes had higher risk on lisinopril versus amlodipine (HR=1.12, P=0.02) or chlorthalidone (1.05, P=0.23), whereas 'A' allele carriers had slightly lower risk (HR=0.92, P=0.33 for lisinopril versus amlodipine; HR=0.88, P=0.08 for lisinopril versus chlorthalidone; P value for interactions 0.04 and 0.03, respectively). ESRD: 'GG' homozygotes had higher risk on lisinopril versus chlorthalidone (HR=1.27, P=0.08), whereas 'A' allele carriers had lower risk (HR=0.64, P=0.12; P value for interaction=0.03).

CONCLUSION

There was evidence of pharmacogenetic effects of FGB-455 on stroke, ESRD, and mortality, suggesting that relative to those homozygous for the common allele, variant allele carriers of the FGB gene at position -455 have a better outcome if randomized to lisinopril than chlorthalidone (for mortality and ESRD) or amlodipine (for mortality and stroke). For the models in which a pharmacogenetic effect was observed, the outcome rates among 'GG' homozygotes were higher in those randomized to lisinopril versus amlodipine or chlorthalidone, whereas minor 'A' allele carriers had lower event rates when randomized to lisinopril versus the other medications.

The corporate bias and the molding of prescription practices: the case of hypertension

Drug management of hypertension has been a noticeable example of the influence of the pharmaceutical industry on prescription practices. The worldwide leading brands of blood pressure-lowering agents are angiotensin receptor-blocking agents, although they are considered to be simply substitutes of angiotensin-converting enzyme (ACE) inhibitors. Commercial strategies have been based on the results of clinical trials sponsored by drug companies. Most of them presented distortions in their planning, presentation or interpretation that favored the drugs from the sponsor, i.e., corporate bias. Atenolol, an ineffective blood pressure agent in elderly individuals, was the comparator drug in several trials. In a re-analysis of the INSIGHT trial, deaths appeared to have been counted twice. The LIFE trial appears in the title of more than 120 reproductions of the main and flawed trial, as a massive strategy of scientific marketing. Most guidelines have incorporated the corporate bias from the original studies, and the evidence from better designed studies, such as the ALLHAT trial, have been largely ignored. In trials published recently corporate influences have touched on ethical limits. In the ADVANCE trial, elderly patients with type 2 diabetes and cardiovascular disease or risk factors, allocated to placebo, were not allowed to use diuretic and full doses of an ACE inhibitor, despite the sound evidence of benefit demonstrated in previous trials. As a consequence, they had a 14% higher mortality rate than the participants allocated to the active treatment arm. This reality should be modified immediately, and a greater independence of the academy from the pharmaceutical industry is necessary.

Diuretics: still essential drugs for the management of hypertension

According to most current international guidelines for hypertension, diuretics are indicated for elderly and black patients, unless they have any of a long list of other preferential indications. These recommendations are mostly based on the results of corporate-sponsored and biased trials, which have unsuccessfully tried to demonstrate the existence of pleiotropic effects of newer agents. Metaregression analyses have shown that the benefits of treatments are directly proportional to the difference in blood pressure between trial arms. New analyses of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack (ALLHAT) trial demonstrated the superiority of chlorthalidone over other agents in the prevention of end-stage renal disease in diabetics and of cardiovascular events in newer cases of diabetes. Despite this evidence, patients continue to withdraw from effective therapies in recent trials. The use of diuretics has also been challenged by the results of the Avoiding Cardiovascular Events in Combination Therapy in Patients Living with Systolic Hypertension (ACCOMPLISH) trial, which employed hydrochlorothiazide, a diuretic with lower potency and duration of action than chlorthalidone. Diuretics are still essential drugs for hypertension management, but diuretics with higher potency and duration of action, such as chlorthalidone, should be preferred.

Antihypertensive medications: benefits of blood pressure lowering and hazards of metabolic effects

Blood pressure reduction is associated with significant reduction in adverse cardiovascular outcomes. Certain blood pressure-lowering drugs have adverse effects on glucose homeostasis, and have been associated with the development of both prediabetes and diabetes during use. There is controversy over the significance of diabetes that develops during treatment with antihypertensives and whether the benefits of blood pressure reduction offset the hazards of dysglycemia that can lead to diabetes. Many treatment guidelines have recently undergone revisions to include consideration for the metabolic effects of antihypertensive drugs, particularly in high-risk populations. This review summarizes the data related to the benefits of blood pressure reduction as well as the adverse metabolic effects and new-onset diabetes associated with some medications.

ALLHAT findings revisited in the context of subsequent analyses, other trials, and meta-analyses

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is reevaluated considering information from new clinical trials, meta-analyses, and recent subgroup and explanatory analyses from ALLHAT, especially those regarding heart failure (HF) and the association of drug treatment with new-onset diabetes mellitus (DM) and its cardiovascular disease (CVD) consequences. Chlorthalidone was superior to (1) doxazosin mesylate in preventing combined CVD (CCVD) (risk ratio [RR], 1.20; 95% confidence interval [CI], 1.13-1.27), especially HF (RR, 1.80; 95% CI, 1.40-2.22) and stroke (RR, 1.26; 95% CI, 1.10-1.46); (2) lisinopril in preventing CCVD (RR, 1.10; 95% CI, 1.05-1.16), including stroke (in black persons only) and HF (RR, 1.20; 95% CI, 1.09-1.34); and (3) amlodipine besylate in preventing HF, overall (by 28%) and in hospitalized or fatal cases (by 26%). Central independent blinded reassessment of HF hospitalizations confirmed each comparison. Results were consistent by age, sex, race (except for stroke and CCVD), DM status, metabolic syndrome status, and renal function level. Neither amlodipine nor lisinopril was superior to chlorthalidone in preventing end-stage renal disease overall, by DM status, or by renal function level. In the chlorthalidone arm, new-onset DM was not significantly associated with CCVD (RR, 0.96; 95% CI, 0.88-2.42). Evidence from subsequent analyses of ALLHAT and other clinical outcome trials confirm that neither alpha-blockers, angiotensin-converting enzyme inhibitors, nor calcium channel blockers surpass thiazide-type diuretics (at appropriate dosage) as initial therapy for reduction of cardiovascular or renal risk. Thiazides are superior in preventing HF, and new-onset DM associated with thiazides does not increase CVD outcomes.

Antihypertensive therapy, new-onset diabetes, and cardiovascular disease

Type 2 diabetes mellitus is a worldwide epidemic with considerable health and economic consequences. Diabetes is an important risk factor for cardiovascular disease, which is the leading cause of death in diabetic patients, and decreasing the incidence of diabetes may potentially reduce the burden of cardiovascular disease. This article discusses the clinical trial evidence for modalities associated with a reduction in the risk of new-onset diabetes, with a focus on the role of antihypertensive agents that block the renin-angiotensin system. Lifestyle interventions and the use of antidiabetic, anti-obesity, and lipid-lowering drugs are also reviewed. An unresolved question is whether decreasing the incidence of new-onset diabetes with non-pharmacologic or pharmacologic intervention will also lower the risk of cardiovascular disease. A large ongoing study is investigating whether the treatment with an oral antidiabetic drug or an angiotensin-receptor blocker will reduce the incidence of new-onset diabetes and cardiovascular disease in patients at high risk for developing diabetes.

Cardiovascular therapies and associated glucose homeostasis: implications across the dysglycemia continuum

Certain cardiovascular drugs have adverse effects on glucose homeostasis, which may lead to important long-term implications for increased risks of adverse outcomes. Thiazide diuretics, niacin, and beta-adrenergic blockers impair glucose homeostasis. However, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have demonstrated beneficial metabolic effects. The newer vasodilating beta-blocking agents and calcium antagonists appear to be metabolically neutral. These considerations, in addition to meticulous attention to blood pressure control and lifestyle changes, have the potential to beneficially modify glycemia and long-term risks. These considerations have particular importance in younger patients who may also have pre-diabetes or the metabolic syndrome and who are likely to require therapy over the course of decades.

Metabolic syndrome

Hirsutism is a finding that can lead to subsequent metabolic diagnoses such as the metabolic syndrome. Metabolic syndrome describes a cluster of cardiometabolic risk factors associated with overweight and obesity. Although it has been the subject of some controversy, perhaps due to the many definitions proposed by different health organizations, metabolic syndrome is clinically relevant in that it is a predictor of vascular risk, even independent of any associated type 2 diabetes. While various definitions may differ in precise cut-off points, they uniformly emphasize key pathophysiologic processes: visceral obesity, dyslipidemia, insulin resistance, and hypertension. Management of metabolic syndrome focuses on methods of reducing the component risk factors, and therapies thus target the above processes as well as controlling inflammation and the prothrombotic state. Treatments can include not only pharmacologic approaches but behavior modification as well.

Do thiazides worsen metabolic syndrome and renal disease? The pivotal roles for hyperuricemia and hypokalemia

PURPOSE OF REVIEW

The aims of this article are to review the current controversies related to the use of thiazide diuretics as first-line treatment of hypertension and to discuss the causal roles for hyperuricemia and hypokalemia on the adverse consequences of thiazide usage.

RECENT FINDINGS

Thiazides significantly reduce morbidity and mortality in hypertensive subjects. There remains, however, debate about thiazide usage as first-line treatment of hypertension. This negative impact of thiazides may be partially attributed to the ability of thiazides to exacerbate features of metabolic syndrome or increase the risk for developing diabetes. Several clinical trials suggest that thiazide-induced hyperuricemia and hypokalemia may account for some of these negative effects. Thiazide treatment is also associated with a decline of renal function in spite of a lowering blood pressure. In this review, we discuss the clinical and experimental evidence supporting a potential role of hyperuricemia and hypokalemia on the development of renal injury and worsening of the metabolic syndrome.

SUMMARY

Hyperuricemia and hypokalemia may have pivotal roles in the exacerbation of the metabolic syndrome in response to thiazides. We propose that controlling serum uric acid and serum potassium could improve thiazide efficacy and also reduce its risk for inducing metabolic syndrome or diabetes.

The metabolic syndrome

The "metabolic syndrome" (MetS) is a clustering of components that reflect overnutrition, sedentary lifestyles, and resultant excess adiposity. The MetS includes the clustering of abdominal obesity, insulin resistance, dyslipidemia, and elevated blood pressure and is associated with other comorbidities including the prothrombotic state, proinflammatory state, nonalcoholic fatty liver disease, and reproductive disorders. Because the MetS is a cluster of different conditions, and not a single disease, the development of multiple concurrent definitions has resulted. The prevalence of the MetS is increasing to epidemic proportions not only in the United States and the remainder of the urbanized world but also in developing nations. Most studies show that the MetS is associated with an approximate doubling of cardiovascular disease risk and a 5-fold increased risk for incident type 2 diabetes mellitus. Although it is unclear whether there is a unifying pathophysiological mechanism resulting in the MetS, abdominal adiposity and insulin resistance appear to be central to the MetS and its individual components. Lifestyle modification and weight loss should, therefore, be at the core of treating or preventing the MetS and its components. In addition, there is a general consensus that other cardiac risk factors should be aggressively managed in individuals with the MetS. Finally, in 2008 the MetS is an evolving concept that continues to be data driven and evidence based with revisions forthcoming.

Hypertension with metabolic syndrome: think thiazides are old hat? ALLHAT says think again

Outcomes support chlorthalidone despite its metabolic profile